It’s been a sewer for 1000 years. The Marne and Oise aren’t supposed to be any better. I’d suggest Lake Geneva (big enough to dilute the pollution) or Annecy (supposedly the cleanest lake in France).
It’s been a sewer for 1000 years
But...but... The Climate Cult Marxist Stooges say Europe is so brilliant and enlightened and we need to be taxed and collectivist just like them....